Karla Christian | Vanderbilt University Medical Center (original) (raw)

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Papers by Karla Christian

Research paper thumbnail of 1303: Group B Streptococcus Infective Endocarditis in a Neonate

Critical Care Medicine, 2014

Research paper thumbnail of Acetaminophen Attenuates Lipid Peroxidation in Children Undergoing Cardiopulmonary Bypass

Pediatric Critical Care Medicine, 2014

Hemolysis, occurring during cardiopulmonary bypass, is associated with lipid peroxidation and pos... more Hemolysis, occurring during cardiopulmonary bypass, is associated with lipid peroxidation and postoperative acute kidney injury. Acetaminophen inhibits lipid peroxidation catalyzed by hemeproteins and in an animal model attenuated rhabdomyolysis-induced acute kidney injury. This pilot study tests the hypothesis that acetaminophen attenuates lipid peroxidation in children undergoing cardiopulmonary bypass. Single-center prospective randomized double-blinded study. University-affiliated pediatric hospital. Thirty children undergoing elective surgical correction of a congenital heart defect. Patients were randomized to acetaminophen (OFIRMEV [acetaminophen] injection; Cadence Pharmaceuticals, San Diego, CA) or placebo every 6 hours for four doses starting before the onset of cardiopulmonary bypass. Markers of hemolysis, lipid peroxidation (isofurans and F2-isoprostanes), and acute kidney injury were measured throughout the perioperative period. Cardiopulmonary bypass was associated with a significant increase in free hemoglobin (from a prebypass level of 9.8 ± 6.2 mg/dL to a peak of 201.5 ± 42.6 mg/dL postbypass). Plasma and urine isofuran and F2-isoprostane concentrations increased significantly during surgery. The magnitude of increase in plasma isofurans was greater than the magnitude in increase in plasma F2-isoprostanes. Acetaminophen attenuated the increase in plasma isofurans compared with placebo (p = 0.02 for effect of study drug). There was no significant effect of acetaminophen on plasma F2-isoprostanes or urinary makers of lipid peroxidation. Acetaminophen did not affect postoperative creatinine, urinary neutrophil gelatinase-associated lipocalin, or prevalence of acute kidney injury. Cardiopulmonary bypass in children is associated with hemolysis and lipid peroxidation. Acetaminophen attenuated the increase in plasma isofuran concentrations. Future studies are needed to establish whether other therapies that attenuate or prevent the effects of free hemoglobin result in more effective inhibition of lipid peroxidation in patients undergoing cardiopulmonary bypass.

Research paper thumbnail of Does Cardiopulmonary Bypass Time Affect Post-Operative Complications Following Pediatric Cardiac Surgery?

Journal of the American College of Cardiology, 2011

Research paper thumbnail of Standardized postoperative handover process improves outcomes in the intensive care unit

Critical Care Medicine, 2012

Research paper thumbnail of Angiotensin-Converting Enzyme Inhibition Alters the Fibrinolytic Response to Cardiopulmonary Bypass

Circulation, 2003

Background— Increased plasminogen activator inhibitor-1 (PAI-1) concentrations after coronary art... more Background— Increased plasminogen activator inhibitor-1 (PAI-1) concentrations after coronary artery bypass grafting (CABG) are associated with increased risk of vein graft occlusion. Because angiotensin II stimulates PAI-1 expression, we tested the hypothesis that preoperative angiotensin-converting enzyme (ACE) inhibition decreases PAI-1 expression after CABG. Methods and Results— We measured the effects of cardiopulmonary bypass (CPB) on PAI-1 antigen and tissue-type plasminogen activator (tPA) antigen and activity in 31 patients taking an ACE inhibitor (ACEI) who were randomized to continue ACEI until the morning of surgery (ACEI group, n=19) or to discontinue it 48 hours before surgery (No-ACEI group, n=12). Arterial blood samples were taken at baseline before CPB, twice during CPB, after separation from CPB, and on postoperative day 1 (POD1). CPB caused an early decrease in PAI-1 antigen, followed by an increase in PAI-1 antigen on POD1 ( P <0.001 for effect of time). ACE i...

Research paper thumbnail of Extracorporeal membrane oxygenation in children after repair of congenital cardiac lesions

The Annals of Thoracic Surgery, 2001

From August 1982 to May 1991, 65 children (32 boys), 1 day to 14 years old, received extracorpore... more From August 1982 to May 1991, 65 children (32 boys), 1 day to 14 years old, received extracorporeal membrane oxygenation (ECMO) 0-50 hours after cardiac surgery. Forty-four (67.7%) were weaned, with 23 (35.4%) survivors. Analysis of 29 pre-ECMO factors including diagnosis, age, sex, blood gas data, systemic pressures, atrial pressures, ventricular function, and renal function was performed. Preoperative systemic ventricular shortening fraction was statistically less in survivors. The need for dialysis and length of support were predictors of survival once ECMO was initiated. There were five late deaths 6 days to 5 years after discharge; none were related to ECMO. The remaining 18 patients have been followed for a mean of 37.5 months (range, 1-85 months). Seventeen are New York Heart Association functional class I, with one patient still hospitalized. ECMO allows for myocardial recovery in the majority of patients with refractory postcardiotomy failure and permits some patients to survive who would not have otherwise.

Research paper thumbnail of Congenitally Corrected Transposition of the Great Arteries: A Unique Case from Iraq

Research paper thumbnail of Developing a Biomarker-Based Predictive Model of Postoperative Outcomes in Children: Pre-Operative NT-Probnp is Independently Associated with Arrhythmia and Thromboses After Congenital Heart Surgery

Journal of the American College of Cardiology

Research paper thumbnail of Neonatal Aortic Arch Reconstruction With Direct Splanchnic Perfusion Avoids Deep Hypothermia

The Annals of Thoracic Surgery

Research paper thumbnail of Abstract 11442: Continued ACE Inhibition Alters the Inflammatory and Fibrinolytic Response to Cardiopulmonary Bypass in Children

Circulation, Nov 23, 2010

Research paper thumbnail of Congenitally corrected transposition of the great arteries: a unique case from Iraq

Pediatric Cardiology, Sep 1, 2009

Research paper thumbnail of Specificity and sensitivity of automated external defibrillator rhythm analysis in infants and children

Annals of Emergency Medicine, Aug 1, 2003

Research paper thumbnail of trial of oral citrulline Nitric oxide precursors and congenital heart surgery: A randomized controlled

Research paper thumbnail of Congenitally corrected transposition of the great arteries: a unique case from Iraq

Pediatric cardiology, 2010

A severely cyanotic 27-month-old Iraqi child was transferred to the United States for surgical tr... more A severely cyanotic 27-month-old Iraqi child was transferred to the United States for surgical treatment of suspected tetralogy of Fallot. Her diagnostic studies showed dextrocardia, congenitally corrected transposition of the great arteries, hypoplastic left-sided ventricle, interrupted inferior vena cava, and severe pulmonic stenosis. Given the anatomic constraints as well as the absence of long-term medical care, the decision was made to pursue single-ventricle palliation. The patient recovered from a superior cavopulmonary anastomosis without event and has since returned to her native Iraq.

Research paper thumbnail of Characteristics Of Pleural Effusions In Patients Undergoing The Fontan Or Glenn Procedures For Congenital Cardiac Defects

B40. CASE REPORTS: PLEURAL DISEASES: DIAGNOSTIC DILEMMAS, 2011

Research paper thumbnail of Pressures Inhaled Nitric Oxide Use in Bidirectional Glenn Anastomosis for Elevated Glenn

Research paper thumbnail of Cardiac surgery after renal transplantation

The American surgeon, 2002

Renal transplantation remains a mainstay of therapy for end-stage renal disease. Cardiac disease ... more Renal transplantation remains a mainstay of therapy for end-stage renal disease. Cardiac disease has a high prevalence in this patient population. This study reviews the factors and outcomes associated with cardiac surgery in renal transplant recipients. We performed a retrospective review of all patients at our institution with a functioning renal allograft at the time of their cardiac surgical procedure. Between June 1971 and April 2000, 2343 patients underwent renal transplantation at Vanderbilt University Medical Center. Twenty-six patients with a functioning renal allograft subsequently underwent a cardiac procedure requiring cardiopulmonary bypass. There were 11 women and 15 men. Twenty-four patients underwent coronary bypass, one had a double valve replacement, and one had a combined coronary bypass/valve replacement. The interval from renal transplant to heart surgery ranged between 0.6 and 227 months (mean 79.1). Operative mortality was zero but there were two hospital deat...

Research paper thumbnail of Cardiac Surgery in Patients With Moderate Renal Impairment

Southern Medical Journal, 2002

There is a paucity of information concerning the results of cardiac surgery in patients with mode... more There is a paucity of information concerning the results of cardiac surgery in patients with moderate impairment of renal function. We reviewed our recent experience to determine the results of operation and the long-term outcome. Since January 1992, we have performed cardiac surgical procedures utilizing total cardiopulmonary bypass on 57 adult patients with preoperative serum creatinine values &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or = 2.0 mg/dL and no history of dialysis. Operative procedures done were coronary artery bypass (39 patients), repeated coronary artery bypass (2), valve replacement with or without coronary artery bypass (12), and other procedures (4). No operative deaths occurred. There were 3 hospital deaths. Only 5 patients required perioperative dialysis; in 5 additional patients, chronic dialysis was begun from 4 to 24 months postoperatively. The surviving patients who were not receiving dialysis had a mean creatinine value of 2.4 mg/dL at most recent follow-up. Adult patients with moderate renal impairment can safely have major cardiac procedures. The majority of patients maintain stable renal function postoperatively. The overall results of cardiac surgery in this patient population are good.

Research paper thumbnail of Clinical Outcomes of 94 Children with Heart Disease Managed with Extra Corporeal Membrane Oxygenation (Ecmo)

Pediatric Critical Care Medicine, 2005

Research paper thumbnail of Methemoglobinemia: Toxicity of inhaled nitric oxide therapy

Pediatric Critical Care Medicine, 2001

Elevation in methemoglobin is a known toxicity of inhaled nitric oxide (NO) therapy. This article... more Elevation in methemoglobin is a known toxicity of inhaled nitric oxide (NO) therapy. This article describes two significant episodes of methemoglobinemia. These cases illustrate the probable cause and the treatment strategies for the potential for delivery of high concentrations of NO, resulting in methemoglobinemia with moderate and even low-dose delivered NO. We propose mechanisms for this occurrence and means of prevention.

Research paper thumbnail of 1303: Group B Streptococcus Infective Endocarditis in a Neonate

Critical Care Medicine, 2014

Research paper thumbnail of Acetaminophen Attenuates Lipid Peroxidation in Children Undergoing Cardiopulmonary Bypass

Pediatric Critical Care Medicine, 2014

Hemolysis, occurring during cardiopulmonary bypass, is associated with lipid peroxidation and pos... more Hemolysis, occurring during cardiopulmonary bypass, is associated with lipid peroxidation and postoperative acute kidney injury. Acetaminophen inhibits lipid peroxidation catalyzed by hemeproteins and in an animal model attenuated rhabdomyolysis-induced acute kidney injury. This pilot study tests the hypothesis that acetaminophen attenuates lipid peroxidation in children undergoing cardiopulmonary bypass. Single-center prospective randomized double-blinded study. University-affiliated pediatric hospital. Thirty children undergoing elective surgical correction of a congenital heart defect. Patients were randomized to acetaminophen (OFIRMEV [acetaminophen] injection; Cadence Pharmaceuticals, San Diego, CA) or placebo every 6 hours for four doses starting before the onset of cardiopulmonary bypass. Markers of hemolysis, lipid peroxidation (isofurans and F2-isoprostanes), and acute kidney injury were measured throughout the perioperative period. Cardiopulmonary bypass was associated with a significant increase in free hemoglobin (from a prebypass level of 9.8 ± 6.2 mg/dL to a peak of 201.5 ± 42.6 mg/dL postbypass). Plasma and urine isofuran and F2-isoprostane concentrations increased significantly during surgery. The magnitude of increase in plasma isofurans was greater than the magnitude in increase in plasma F2-isoprostanes. Acetaminophen attenuated the increase in plasma isofurans compared with placebo (p = 0.02 for effect of study drug). There was no significant effect of acetaminophen on plasma F2-isoprostanes or urinary makers of lipid peroxidation. Acetaminophen did not affect postoperative creatinine, urinary neutrophil gelatinase-associated lipocalin, or prevalence of acute kidney injury. Cardiopulmonary bypass in children is associated with hemolysis and lipid peroxidation. Acetaminophen attenuated the increase in plasma isofuran concentrations. Future studies are needed to establish whether other therapies that attenuate or prevent the effects of free hemoglobin result in more effective inhibition of lipid peroxidation in patients undergoing cardiopulmonary bypass.

Research paper thumbnail of Does Cardiopulmonary Bypass Time Affect Post-Operative Complications Following Pediatric Cardiac Surgery?

Journal of the American College of Cardiology, 2011

Research paper thumbnail of Standardized postoperative handover process improves outcomes in the intensive care unit

Critical Care Medicine, 2012

Research paper thumbnail of Angiotensin-Converting Enzyme Inhibition Alters the Fibrinolytic Response to Cardiopulmonary Bypass

Circulation, 2003

Background— Increased plasminogen activator inhibitor-1 (PAI-1) concentrations after coronary art... more Background— Increased plasminogen activator inhibitor-1 (PAI-1) concentrations after coronary artery bypass grafting (CABG) are associated with increased risk of vein graft occlusion. Because angiotensin II stimulates PAI-1 expression, we tested the hypothesis that preoperative angiotensin-converting enzyme (ACE) inhibition decreases PAI-1 expression after CABG. Methods and Results— We measured the effects of cardiopulmonary bypass (CPB) on PAI-1 antigen and tissue-type plasminogen activator (tPA) antigen and activity in 31 patients taking an ACE inhibitor (ACEI) who were randomized to continue ACEI until the morning of surgery (ACEI group, n=19) or to discontinue it 48 hours before surgery (No-ACEI group, n=12). Arterial blood samples were taken at baseline before CPB, twice during CPB, after separation from CPB, and on postoperative day 1 (POD1). CPB caused an early decrease in PAI-1 antigen, followed by an increase in PAI-1 antigen on POD1 ( P <0.001 for effect of time). ACE i...

Research paper thumbnail of Extracorporeal membrane oxygenation in children after repair of congenital cardiac lesions

The Annals of Thoracic Surgery, 2001

From August 1982 to May 1991, 65 children (32 boys), 1 day to 14 years old, received extracorpore... more From August 1982 to May 1991, 65 children (32 boys), 1 day to 14 years old, received extracorporeal membrane oxygenation (ECMO) 0-50 hours after cardiac surgery. Forty-four (67.7%) were weaned, with 23 (35.4%) survivors. Analysis of 29 pre-ECMO factors including diagnosis, age, sex, blood gas data, systemic pressures, atrial pressures, ventricular function, and renal function was performed. Preoperative systemic ventricular shortening fraction was statistically less in survivors. The need for dialysis and length of support were predictors of survival once ECMO was initiated. There were five late deaths 6 days to 5 years after discharge; none were related to ECMO. The remaining 18 patients have been followed for a mean of 37.5 months (range, 1-85 months). Seventeen are New York Heart Association functional class I, with one patient still hospitalized. ECMO allows for myocardial recovery in the majority of patients with refractory postcardiotomy failure and permits some patients to survive who would not have otherwise.

Research paper thumbnail of Congenitally Corrected Transposition of the Great Arteries: A Unique Case from Iraq

Research paper thumbnail of Developing a Biomarker-Based Predictive Model of Postoperative Outcomes in Children: Pre-Operative NT-Probnp is Independently Associated with Arrhythmia and Thromboses After Congenital Heart Surgery

Journal of the American College of Cardiology

Research paper thumbnail of Neonatal Aortic Arch Reconstruction With Direct Splanchnic Perfusion Avoids Deep Hypothermia

The Annals of Thoracic Surgery

Research paper thumbnail of Abstract 11442: Continued ACE Inhibition Alters the Inflammatory and Fibrinolytic Response to Cardiopulmonary Bypass in Children

Circulation, Nov 23, 2010

Research paper thumbnail of Congenitally corrected transposition of the great arteries: a unique case from Iraq

Pediatric Cardiology, Sep 1, 2009

Research paper thumbnail of Specificity and sensitivity of automated external defibrillator rhythm analysis in infants and children

Annals of Emergency Medicine, Aug 1, 2003

Research paper thumbnail of trial of oral citrulline Nitric oxide precursors and congenital heart surgery: A randomized controlled

Research paper thumbnail of Congenitally corrected transposition of the great arteries: a unique case from Iraq

Pediatric cardiology, 2010

A severely cyanotic 27-month-old Iraqi child was transferred to the United States for surgical tr... more A severely cyanotic 27-month-old Iraqi child was transferred to the United States for surgical treatment of suspected tetralogy of Fallot. Her diagnostic studies showed dextrocardia, congenitally corrected transposition of the great arteries, hypoplastic left-sided ventricle, interrupted inferior vena cava, and severe pulmonic stenosis. Given the anatomic constraints as well as the absence of long-term medical care, the decision was made to pursue single-ventricle palliation. The patient recovered from a superior cavopulmonary anastomosis without event and has since returned to her native Iraq.

Research paper thumbnail of Characteristics Of Pleural Effusions In Patients Undergoing The Fontan Or Glenn Procedures For Congenital Cardiac Defects

B40. CASE REPORTS: PLEURAL DISEASES: DIAGNOSTIC DILEMMAS, 2011

Research paper thumbnail of Pressures Inhaled Nitric Oxide Use in Bidirectional Glenn Anastomosis for Elevated Glenn

Research paper thumbnail of Cardiac surgery after renal transplantation

The American surgeon, 2002

Renal transplantation remains a mainstay of therapy for end-stage renal disease. Cardiac disease ... more Renal transplantation remains a mainstay of therapy for end-stage renal disease. Cardiac disease has a high prevalence in this patient population. This study reviews the factors and outcomes associated with cardiac surgery in renal transplant recipients. We performed a retrospective review of all patients at our institution with a functioning renal allograft at the time of their cardiac surgical procedure. Between June 1971 and April 2000, 2343 patients underwent renal transplantation at Vanderbilt University Medical Center. Twenty-six patients with a functioning renal allograft subsequently underwent a cardiac procedure requiring cardiopulmonary bypass. There were 11 women and 15 men. Twenty-four patients underwent coronary bypass, one had a double valve replacement, and one had a combined coronary bypass/valve replacement. The interval from renal transplant to heart surgery ranged between 0.6 and 227 months (mean 79.1). Operative mortality was zero but there were two hospital deat...

Research paper thumbnail of Cardiac Surgery in Patients With Moderate Renal Impairment

Southern Medical Journal, 2002

There is a paucity of information concerning the results of cardiac surgery in patients with mode... more There is a paucity of information concerning the results of cardiac surgery in patients with moderate impairment of renal function. We reviewed our recent experience to determine the results of operation and the long-term outcome. Since January 1992, we have performed cardiac surgical procedures utilizing total cardiopulmonary bypass on 57 adult patients with preoperative serum creatinine values &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or = 2.0 mg/dL and no history of dialysis. Operative procedures done were coronary artery bypass (39 patients), repeated coronary artery bypass (2), valve replacement with or without coronary artery bypass (12), and other procedures (4). No operative deaths occurred. There were 3 hospital deaths. Only 5 patients required perioperative dialysis; in 5 additional patients, chronic dialysis was begun from 4 to 24 months postoperatively. The surviving patients who were not receiving dialysis had a mean creatinine value of 2.4 mg/dL at most recent follow-up. Adult patients with moderate renal impairment can safely have major cardiac procedures. The majority of patients maintain stable renal function postoperatively. The overall results of cardiac surgery in this patient population are good.

Research paper thumbnail of Clinical Outcomes of 94 Children with Heart Disease Managed with Extra Corporeal Membrane Oxygenation (Ecmo)

Pediatric Critical Care Medicine, 2005

Research paper thumbnail of Methemoglobinemia: Toxicity of inhaled nitric oxide therapy

Pediatric Critical Care Medicine, 2001

Elevation in methemoglobin is a known toxicity of inhaled nitric oxide (NO) therapy. This article... more Elevation in methemoglobin is a known toxicity of inhaled nitric oxide (NO) therapy. This article describes two significant episodes of methemoglobinemia. These cases illustrate the probable cause and the treatment strategies for the potential for delivery of high concentrations of NO, resulting in methemoglobinemia with moderate and even low-dose delivered NO. We propose mechanisms for this occurrence and means of prevention.